First of all, to avoid confusion, I'd remove all hibernate.cache.region.jbc2.* properties that belong to another cache provider.

I think the key here is hibernate.cache.infinispan.use_synchronization which you have set it to false. We've seen performance increase quite noticeably when that parameter is true. In fact, true is the default value and so I'd remove this property altogether. Let the Hibernate/Infinispan layer decide what's best here